Published: 8/5/2026
24-Month Field Report: Duplex Double-Eccentric Butterfly Valves in Refinery Catalytic Flue Gas Service
Project Background & Customer Pain Points
Flue gas piping on the waste-heat boiler of a catalytic cracking unit at a major coastal refinery faced severe conditions of high temperature, dust, and sulfur content. Previously used imported wafer butterfly valves suffered frequent seat wear and seal leakage, with an average service life of under 8 months. Each repair required more than 72 hours of downtime, and annual maintenance costs remained persistently high.
Selected Solution
After on-site surveys and condition analysis, the Handa Valve technical team delivered a customized 2205 duplex stainless steel double-eccentric soft-seated butterfly valve solution:
- Material upgrade: Body and disc in 2205 duplex steel, with significantly better chloride and H₂S corrosion resistance than 316L
- Structural advantage: The double-eccentric design lifts the disc from the seat immediately upon opening, greatly reducing wear
- Sealing: High-temperature RPTFE soft seat combined with a metal seat for dual protection
- Batch replacement: 32 valves in DN300-DN600 replaced in phase one
24-Month Field Data
| Metric | Previous Imported Valve | Handa Double-Eccentric Valve |
|---|---|---|
| Average service life | < 8 months | ≥ 24 months |
| Seal leakage | Seepage in mid-life | Zero leakage throughout |
| Annual maintenance downtime | 72+ hours | 0 (maintenance-free) |
| Procurement cost | Premium import pricing | ~40% lower |
Customer Feedback
"In these 24 months, none of the 32 valves has leaked even once. Our waste-heat boiler inspection cycle has extended from twice a year to once every two years. Handa provided not only qualified products but also one-stop service from selection to after-sales." — Equipment Director of the refinery
Key Takeaways
High-temperature flue gas service tests a valve in every dimension. Through the combination of material upgrade + structural innovation + customized service, Handa helped the customer leap from "frequent repairs" to "long-cycle maintenance-free" operation — a replicable model for valve localization in similar refinery units.